password

Arguments:
editable-text

Returns the value of the password property of its argument, which must
be an editable-text control. This
property may be used to prevent others from seeing what the end user
is typing into an editable-text control, by
displaying an asterisk or other special character for each character
that the user actually enters. The real characters are still stored in
the string value of the control as usual. Password masking can be
switched on and off for an existing editable-text by calling the
setf of this
function.

The value may be either nil (the default) for
ordinary text display without password masking,
t to display an
asterisk for each real character, or a Lisp character to display that
character for each real character.